Hybrid modelling and simulation of the torsional vibration of vehicle driveline systems

2001 ◽  
Vol 215 (2) ◽  
pp. 217-229 ◽  
Author(s):  
A Farshidianfar ◽  
M Ebrahimi ◽  
H Bartlett
Keyword(s):  
Degrees Of Freedom ◽  
Governing Equations ◽  
Dynamic Interactions ◽  
Hybrid Modelling ◽  
Power Train ◽  
Lumped Model ◽  
Vibration Responses ◽  
Gear Contact ◽  
Many Sources ◽  
Train System

Vehicle drivelines are lightly damped non-linear systems possessing many degrees of freedom with dynamic interactions between the various subsystems. There are many sources of excitation such as torsional impact caused by the take-up of backlash in the power train system. Such sources of excitation exist in transmission backlash, in driveline splines and in pinion to ring gear contact in the differential. Abrupt application or release of the throttle in slowly moving traffic or rapid engagement of the clutch can be followed by noise and vibration responses referred to in the industry as ‘clonk’. This paper presents a method of modelling a vehicle driveline which can identify the phenomena known as ‘clonk’ and ‘shuffle’. This model is based on the assumption that vehicle drivelines can be considered as partially lumped and partially distributed, which for systems of this type is wholly appropriate. In doing this it is possible to derive an analytical solution to the governing equations, which has not been considered previously. The results from this model are compared with a totally lumped model of the vehicle driveline for comparison.

DESIGN AND DEVELOPMENT OF AN EFFICIENT COMPUTER SIMULATION MODEL FOR RESPONSE ANALYSIS OF A MOORED SEMI-SUBMERSIBLE

2021 ◽  
Vol 161 (A1) ◽  
Author(s):  
V Domala ◽  
R Sharma
Keyword(s):  
Computer Simulation ◽  
Simulation Model ◽  
Degrees Of Freedom ◽  
Experimental Results ◽  
Response Analysis ◽  
Computer Simulation Model ◽  
Governing Equations ◽  
Design And Development ◽  
Mooring Lines ◽  
Steel Wires

This paper presents the design and development of an efficient modular ‘Computer Simulation Model (CSM)’ for response analysis of a moored semi-submersible. The computer simulation model is designed in two split models (i.e. computational and experimental models) and each of these models consists of various modules. The modules are developed from basic governing equations related to motion and modules are integrated and we aim for a seamless integration. The moored semi-submersible is represented mathematically as six degrees of freedom dynamic system and the coupling effects between the structure and mooring lines are considered. The basic geometric configuration of semi- submersible is modelled and analyzed for stability computations in MS-Excel*TM and then the basic governing equations related to motion are modelled mathematically in a module and solved numerically with Ansys-AQWA**TM. The computational model is validated and verified with some available experimental results. The CSM is utilized to study the surge and sway responses with respect to the horizontal range of mooring lines and our results show good validation with the existing experimental results. Our presented results show that the fibre wires have minimum steady state response in surge and sway degrees of freedom as compared with the steel wires. However, they have large drift as compared with steel wires. Finally, we show that the computer simulation model can help in detailed analysis of responses and results can be utilized for design and development of new age semi-submersibles for optimum performances for a given set of parameters.

Theoretical and Experimental Study of the Nonlinearly Coupled Heave, Pitch, and Roll Motions of a Ship in Longitudinal Waves

1993 ◽  
Author(s):  
I. G. Oh ◽  
A. H. Nayfeh ◽  
D. T. Mook
Keyword(s):  
Large Amplitude ◽  
Degrees Of Freedom ◽  
Excitation Frequency ◽  
Force Response ◽  
Governing Equations ◽  
Response Curves ◽  
Varying Coefficients ◽  
Jump Phenomena ◽  
Time Varying Coefficients ◽  
Three Degrees Of Freedom

Abstract The loss of dynamic stability and the resulting large-amplitude roll of a vessel in a head or following sea were studied theoretically and experimentally. A ship model with three degrees of freedom (roll, pitch, heave) was considered. The governing equations for the heave and pitch modes were linearized and their harmonic solutions were coupled with the nonlinear equation governing roll. The resulting equation, which has time-varying coefficients, was used to predict the response in roll. The principal parametric resonance was considered in which the excitation frequency is twice the natural frequency in roll. Force-response curves were obtained. The existence of jump phenomena and multiple stable solutions for the case of subcritical instability was observed in the experiments and found to be in good qualitative agreement with the results predicted by the theory. The experiments also revealed that the large-amplitude roll is dependent on the location of the model in the standing waves.

scholarly journals Characteristics of Low Frequency Non-Synchronous Vibrations Induced by an Epicyclic Gearbox in Gas Turbogenerator Applications

1998 ◽  
Author(s):  
A. K. Rakhit ◽  
G. A. Cornejo ◽  
G. J. Lack
Keyword(s):  
Low Frequency ◽  
Output Shaft ◽  
Power Train ◽  
Backward Whirl ◽  
Considerable Length ◽  
Potential Damage ◽  
Generator Sets ◽  
Star Configuration ◽  
Train System ◽  
Total Elimination

Epicyclic gearboxes of star configuration running at partial loads were found to induce non-synchronous (not related to speed) low-frequency vibrations, besides low level sub-synchronous (speed related) which were transmitted to other parts of a turbogenerator power train. At certain loads, the amplitudes of the non-synchronous vibrations were high enough to cause potential damage to sleeve bearings used in the power train system if a generator set would run for any considerable length of time at these loads. It was also observed that a very small increase in load above a certain limit (about 18% of full load) resulted in almost total elimination of these vibrations. Analysis of test data showed the non-synchronous vibrations were due to ‘backward whirl’ motion of gearbox output shaft in its sleeve bearings. Higher damping in the bearings was considered to be one of the most effective methods to suppress backward whirl of a shaft and hence, the non-synchronous vibrations. Accordingly, a new set of gearbox output shaft sleeve bearings was designed for higher damping that would allow these types of generator sets to run at partial and full loads without any detrimental vibration.

Advances in the Power train System of Honda FCX Clarity Fuel Cell Vehicle

2009 ◽  
Author(s):  
Minoru Matsunaga ◽  
Tatsuya Fukushima ◽  
Kuniaki Ojima
Keyword(s):  
Fuel Cell ◽  
Fuel Cell Vehicle ◽  
Power Train ◽  
Train System

scholarly journals Quasi-Static Characteristics and Vibration Responses Analysis of Helical Geared Rotor System with Random Cumulative Pitch Deviations

2020 ◽  
Vol 10 (12) ◽  
pp. 4403
Author(s):  
Bing Yuan ◽  
Geng Liu ◽  
Lan Liu
Keyword(s):  
Degrees Of Freedom ◽  
Transmission Error ◽  
Rotor System ◽  
Dynamic Responses ◽  
Contact Ratio ◽  
Tooth Contact Analysis ◽  
Long Period ◽  
Light Load ◽  
Vibration Responses ◽  
Loaded Tooth Contact Analysis

As one of the long period gear errors, the effects of random cumulative pitch deviations on mesh excitations and vibration responses of a helical geared rotor system (HGRS) are investigated. The long-period mesh stiffness (LPMS), static transmission error (STE), as well as composite mesh error (CMS), and load distributions of helical gears are calculated using an enhanced loaded tooth contact analysis (LTCA) model. A dynamic model with multi degrees of freedom (DOF) is employed to predict the vibration responses of HGRS. Mesh excitations and vibration responses analysis of unmodified HGRS are conducted in consideration of random cumulative pitch deviations. The results indicate that random cumulative pitch deviations have significant effects on mesh excitations and vibration responses of HGRS. The curve shapes of STE and CMS become irregular when the random characteristic of cumulative pitch deviations is considered, and the appearance of partial contact loss in some mesh cycles leads to decreased LPMS when load torque is relatively low. Vibration modulation phenomenon can be observed in dynamic responses of HGRS. In relatively light load conditions, the amplitudes of sideband frequencies become larger than that of mesh frequency and its harmonics (MFIHs) because of relatively high contact ratio. The influences of random cumulative pitch deviations on the vibration responses of modified HGRS are also discussed.

scholarly journals Finite Element Vibration Analysis of Laminated Composite Folded Plate Structures

1999 ◽  
Vol 6 (5-6) ◽  
pp. 273-283 ◽  
Author(s):  
A. Guha Niyogi ◽  
M.K. Laha ◽  
P.K. Sinha
Keyword(s):  
Finite Element ◽  
Forced Vibration ◽  
Vibration Analysis ◽  
Degrees Of Freedom ◽  
Laminated Composite ◽  
Mode Shapes ◽  
Plate Structures ◽  
Drilling Degree Of Freedom ◽  
Vibration Responses ◽  
Forced Vibration Analysis

A nine-noded Lagrangian plate bending finite element that incorporates first-order transverse shear deformation and rotary inertia is used to predict the free and forced vibration response of laminated composite folded plate structures. A 6 × 6 transformation matrix is derived to transform the system element matrices before assembly. The usual five degrees-of-freedom per node is appended with an additional drilling degree of freedom in order to fit the transformation. The present finite element results show good agreement with the available semi-analytical solutions and finite element results. Parametric studies are conducted for free and forced vibration analysis for laminated folded plates, with reference to crank angle, fibre angle and stacking sequence. The natural frequencies and mode shapes, and forced vibration responses furnished here may serve as a benchmark for future investigations.

Effects of Flexibility and Damping on Momentum Transfer During Locking of Two Moving Links, Part I: Numerical Simulation

1998 ◽  
Vol 65 (2) ◽  
pp. 479-484 ◽  
Author(s):  
W. Szyszkowski ◽  
K. Fielden
Keyword(s):  
Numerical Simulation ◽  
Momentum Transfer ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Slow Motion ◽  
Critical Values ◽  
Governing Equations ◽  
Two Degrees Of Freedom

The system consisting of two links and two joints is examined. The joints are idealy frictionless when unlocked. Due to flexibility of the links, the locking generates some damped vibrations. It is demonstrated that the presence of these vibrations, even of very small and seemingly neglegible amplitudes, have dramatic effects on the after-locking motion of the links. Depending on the level of flexibility and damping involved, the locking triggers a large-scale “slow” motion that may have either oscillatory or circular (clockwise or counterclockwise) characters. The links will stop at some resting configuration only at certain “critical” values of damping. The set of “critical dampings” seems to be infinite, though only two degrees-of-freedom are used to model the system. Governing equations for these phenomena are derived and discussed in Part II of this paper.

scholarly journals Coupled Vibration Analysis of Submerged Floating Tunnel System in Wave and Current

2018 ◽  
Vol 8 (8) ◽  
pp. 1311 ◽  
Author(s):  
Zhengyang Chen ◽  
Yiqiang Xiang ◽  
Heng Lin ◽  
Ying Yang
Keyword(s):  
Degrees Of Freedom ◽  
Natural Vibration ◽  
Structural Parameters ◽  
Wave Force ◽  
Natural Vibration Frequency ◽  
Governing Equations ◽  
Nonlinear Dynamic Response ◽  
Submerged Floating Tunnel ◽  
Installation Depth ◽  
Tunnel System

Submerged floating tunnel (SFT) is an innovative underwater structure for crossing long straits, which withstands the effects of water wave and current throughout its lifecycle. This paper proposes a theoretical approach to investigate the nonlinear dynamic response of the SFT tube-cable system under combined parametric excitation and hydrodynamic forcing excitations (i.e., wave and vortex-induced loading). Firstly, the governing equations of the SFT system considering the coupled degrees of freedom in the tube and cable are established based on the Hamilton principle and are solved numerically. Then, several representative cases are analyzed to reveal the dynamic characteristics of the SFT. Finally, some key parameters are discussed, such as the wave and current conditions and the structural parameters. The results show that when the flow velocity reaches a certain value, the vortex-induced vibration (VIV) of the anchor-cables will excite a strong resonance in the structure. The displacement amplitude of the SFT increases with the increase of the wave height. Gravity-buoyance ratio (GBR) of the tube and the inclined mooring angle (IMA) of the cables jointly determine the natural vibration frequency of the SFT. The influence of the wave force on the tube is limited when the installation depth of SFT is more than 40 m.

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